Abstract. In order to accurately define the superplastic forming (SPF) conditions of Ti-6Al-4V material, an understanding stress-strain behaviour, initial microstructure, and their evolution during deformation are required. material with microstructure beneficial for SPF was superplastically tested according ASTM E2448 standard considering a wide range in terms temperatures (750°C – 830°C) stra...

Low-temperature superplasticity (LTS) is crucial to reduce manufacturing cost and enhance the applications of superplastic forming. It well known that grain refinement key point decrease temperature at which attained. Therefore, ultrafine-grained (UFG) materials have become attractive for achieving LTS. Severe plastic deformation (SPD) techniques provide abnormal refinement, thus they been used...

In this study, the rheological characteristics of a titanium alloy have been obtained by multi-dome bulging test. Free bulging process is an experimental technique that can be used to characterize material in conditions of biaxial tension during superplastic, as well as conventional, hot forming. The constitutive constants are calculated on a base of the information about the bulge geometry, ap...

We consider a mathematical model for the quasi-static deformation of a thinning sheet. The model couples a first-order equation for the thickness of the sheet to a prescribed curvature equation for the displacement of the sheet. We prove a local in time existence and uniqueness theorem for this system when the sheet can be written as a graph. A contact problem is formulated for a sheet constrai...